Merge pull request #10763 from senny/10758_to_sentence_with_blank_elements

test-case for `Array#to_sentence` with `blank?` items.

activesupport/test/core_ext/array_ext_test.rb

@@ -96,6 +96,10 @@ class ArrayExtToSentenceTests < ActiveSupport::TestCase
     assert_equal "one two, and three", ['one', 'two', 'three'].to_sentence(options)
     assert_equal({ words_connector: ' ' }, options)
   end
+
+  def test_with_blank_elements
+    assert_equal ", one, , two, and three", [nil, 'one', '', 'two', 'three'].to_sentence
+  end
 end
 
 class ArrayExtToSTests < ActiveSupport::TestCase